def _apply_action(self, action, child_data, overall_data):
"""Apply actions to each layer that is rendered.
Supported actions include:
* ``merge`` - a "deep" merge that layers new and modified data onto
existing data
* ``replace`` - overwrite data at the specified path and replace it
with the data given in this document
* ``delete`` - remove the data at the specified path
:raises UnsupportedActionMethod: If the layering action isn't found
among ``self.SUPPORTED_METHODS``.
:raises MissingDocumentKey: If a layering action path isn't found
in the child document.
"""
method = action['method']
if method not in self._SUPPORTED_METHODS:
raise errors.UnsupportedActionMethod(
action=action, document=child_data)
# Use copy to prevent these data from being updated referentially.
overall_data = copy.deepcopy(overall_data)
child_data = copy.deepcopy(child_data)
# If None is used, then consider it as a placeholder and coerce the
# data into a dictionary.
if overall_data is None:
overall_data = {}
if child_data is None:
child_data = {}
action_path = action['path']
if action_path.startswith('.data'):
action_path = action_path[5:]
elif action_path.startswith('$.data'):
action_path = action_path[6:]
if not (action_path.startswith('.') or action_path.startswith('$.')):
action_path = '.' + action_path
if method == self._DELETE_ACTION:
if action_path == '.':
overall_data.data = {}
else:
from_child = utils.jsonpath_parse(overall_data.data,
action_path)
if from_child is None:
raise errors.MissingDocumentKey(
child_schema=child_data.schema,
child_layer=child_data.layer,
child_name=child_data.name,
parent_schema=overall_data.schema,
parent_layer=overall_data.layer,
parent_name=overall_data.name,
action=action)
engine_utils.deep_delete(from_child, overall_data.data, None)
elif method == self._MERGE_ACTION:
from_overall = utils.jsonpath_parse(overall_data.data, action_path)
from_child = utils.jsonpath_parse(child_data.data, action_path)
if from_child is None:
raise errors.MissingDocumentKey(
child_schema=child_data.schema,
child_layer=child_data.layer,
child_name=child_data.name,
parent_schema=overall_data.schema,
parent_layer=overall_data.layer,
parent_name=overall_data.name,
action=action)
# If both the child and parent data are dictionaries, then
# traditional merging is possible using JSON path resolution.
# Otherwise, JSON path resolution is not possible, so the only
# way to perform layering is to prioritize the child data over
# that of the parent. This applies when the child data is a
# non-dict, the parent data is a non-dict, or both.
if all(isinstance(x, dict) for x in (from_overall, from_child)):
engine_utils.deep_merge(from_overall, from_child)
else:
LOG.info('Child data is type: %s for [%s, %s] %s. Parent data '
'is type: %s for [%s, %s] %s. Both must be '
'dictionaries for regular JSON path merging to work. '
'Because this is not the case, child data will be '
'prioritized over parent data for "merge" action.',
type(from_child), child_data.schema, child_data.layer,
child_data.name, type(from_overall),
overall_data.schema, overall_data.layer,
overall_data.name)
from_overall = from_child
if from_overall is not None:
overall_data.data = utils.jsonpath_replace(
overall_data.data, from_overall, action_path)
else:
overall_data.data = utils.jsonpath_replace(
overall_data.data, from_child, action_path)
elif method == self._REPLACE_ACTION:
from_child = utils.jsonpath_parse(child_data.data, action_path)
if from_child is None:
raise errors.MissingDocumentKey(
child_schema=child_data.schema,
child_layer=child_data.layer,
child_name=child_data.name,
parent_schema=overall_data.schema,
parent_layer=overall_data.layer,
parent_name=overall_data.name,
action=action)
overall_data.data = utils.jsonpath_replace(
overall_data.data, from_child, action_path)
return overall_data
def _apply_action(self, action, child_data, overall_data):
"""Apply actions to each layer that is rendered.
Supported actions include:
* `merge` - a "deep" merge that layers new and modified data onto
existing data
* `replace` - overwrite data at the specified path and replace it
with the data given in this document
* `delete` - remove the data at the specified path
"""
method = action['method']
if method not in self.SUPPORTED_METHODS:
raise errors.UnsupportedActionMethod(action=action,
document=child_data)
# Use copy prevent these data from being updated referentially.
overall_data = copy.deepcopy(overall_data)
child_data = copy.deepcopy(child_data)
rendered_data = overall_data
# Remove empty string paths and ensure that "data" is always present.
path = action['path'].split('.')
path = [p for p in path if p != '']
path.insert(0, 'data')
last_key = 'data' if not path[-1] else path[-1]
for attr in path:
if attr == path[-1]:
break
rendered_data = rendered_data.get(attr)
child_data = child_data.get(attr)
if method == 'delete':
# If the entire document is passed (i.e. the dict including
# metadata, data, schema, etc.) then reset data to an empty dict.
if last_key == 'data':
rendered_data['data'] = {}
elif last_key in rendered_data:
del rendered_data[last_key]
elif last_key not in rendered_data:
# If the key does not exist in `rendered_data`, this is a
# validation error.
raise errors.MissingDocumentKey(child=child_data,
parent=rendered_data,
key=last_key)
elif method == 'merge':
if last_key in rendered_data and last_key in child_data:
# If both entries are dictionaries, do a deep merge. Otherwise
# do a simple merge.
if (isinstance(rendered_data[last_key], dict)
and isinstance(child_data[last_key], dict)):
engine_utils.deep_merge(rendered_data[last_key],
child_data[last_key])
else:
rendered_data.setdefault(last_key, child_data[last_key])
elif last_key in child_data:
rendered_data.setdefault(last_key, child_data[last_key])
else:
# If the key does not exist in the child document, this is a
# validation error.
raise errors.MissingDocumentKey(child=child_data,
parent=rendered_data,
key=last_key)
elif method == 'replace':
if last_key in rendered_data and last_key in child_data:
rendered_data[last_key] = child_data[last_key]
elif last_key in child_data:
rendered_data.setdefault(last_key, child_data[last_key])
elif last_key not in child_data:
# If the key does not exist in the child document, this is a
# validation error.
raise errors.MissingDocumentKey(child=child_data,
parent=rendered_data,
key=last_key)
return overall_data